Clinical Trials

During any minimally invasive surgery case, 5-25mm size incisions need to be made to gain
access to the abdomen. One of the most difficult, time-consuming, and sometimes unreliable
parts of the case is closing these incisions, especially in obese patients. This is mainly
because these incisions are very small and the layer that needs to be closed (fascia) rests
deep underneath the skin and fat tissue of the abdominal wall. Two of the investigators (CM
and BS) have developed at Stanford an instrument that allows for an easier and more reliable
closure of these wounds. The purpose of this study is to test this instrument in the closure
of laparoscopic wounds in obese patients undergoing laparoscopic gastric bypass surgery.

Publications

All Publications

Abstract

Innovation is the process through which new scientific discoveries are developed and promoted from bench to bedside. In an effort to encourage young entrepreneurs in this area, Stanford Biodesign developed a medical device innovation training program focused on need-based innovation. The program focuses on teaching systematic evaluation of healthcare needs, invention, and concept development. This process can be applied to any field of medicine, including Pediatric Surgery. Similar training programs have gained traction throughout the United States and beyond. Equally important to process in the success of these programs is an institutional culture that supports transformative thinking. Key components of this culture include risk tolerance, patience, encouragement of creativity, management of conflict, and networking effects.

Abstract

In summary, the Task Force does understand that change is difficult and, in the circumstance of the US health care environment, quite complex. Having acknowledged this, the Task Force firmly believes that if optimal resource standards are clear, providers will act in the best interests of their patients, infants, and children undergoing surgery in this circumstance. We intend to provide evidence to this point, to define optimal resources, and to facilitate this process. The hope and the underlying intent of these recommendations is to insure that every infant and child undergoing a surgical procedure in the United States will receive his or her care in an environment that offers all of the facilities, equipment, and, most especially, access to the professional providers who have the appropriate background and training to provide optimal care. This must be done while balancing the issues of access, staff, and the need to improve the value proposition. The Task Force is unanimous in its intent to advocate for this agenda.

Firearm Injuries and Children: A Policy Statement of the American Pediatric Surgical AssociationJOURNAL OF THE AMERICAN COLLEGE OF SURGEONSNance, M. L., Krummel, T. M., Oldham, K. T.2013; 217 (5): 940-946

Abstract

The Stanford Biodesign Program began in 2001 with a mission of helping to train leaders in biomedical technology innovation. A key feature of the program is a full-time postgraduate fellowship where multidisciplinary teams undergo a process of sourcing clinical needs, inventing solutions and planning for implementation of a business strategy. The program places a priority on needs identification, a formal process of selecting, researching and characterizing needs before beginning the process of inventing. Fellows and students from the program have gone on to careers that emphasize technology innovation across industry and academia. Biodesign trainees have started 26 companies within the program that have raised over $200 million and led to the creation of over 500 new jobs. More importantly, although most of these technologies are still at a very early stage, several projects have received regulatory approval and so far more than 150,000 patients have been treated by technologies invented by our trainees. This paper reviews the initial outcomes of the program and discusses lessons learned and future directions in terms of training priorities.

Abstract

We conducted a systematic review of published literature to gain a better understanding of the impact of advanced fellowships on surgical resident training and education.As fellowship opportunities rise, resident training may be adversely impacted.PubMed, MEDLINE, Scopus, BIOSIS, Web of Science, and a manual search of article bibliographies. Of the 139 citations identified through the initial electronic search and screened for possible inclusion, 23 articles were retained and accepted for this review. Data were extracted regarding surgical specialty, methodology, sample population, outcomes measured, and results.Eight studies retrospectively compared the eras before and after the introduction of a fellowship or trended data over time. Approximately half used data from a single institution, whereas the other half used some form of national data or survey. Only 3 studies used national case data. Fourteen studies looked at general surgery, 6 at obstetrics-gynecology, 2 at urology, and 1 at otolaryngology. Only one study concluded that fellowships have a generally positive impact on resident education, whereas 9 others found a negative impact. The remaining 13 studies found mixed results (n = 6) or minimal to no impact (n = 7).The overall impact of advanced surgical fellowships on surgical resident education and training remains unclear, as most studies rely on limited data of questionable generalizability. A careful study of the national database of surgery resident case logs is essential to better understand how early surgical specialization and fellowships will impact the future of general surgery education.

Abstract

Replacement conduits carry significant morbidity in long gap esophageal atresia. Surgical myotomies can lengthen the esophagus, but have not gained widespread adoption due to long-term dilatation. The aim of this study is to assess the feasibility of an emerging minimally invasive technique of submucosal endoscopic myotomy for esophageal lengthening.Bilateral submucosal lengthening endoscopic myotomies (BSLEM) were performed in three swine. Circular esophageal muscle fibers were selectively divided in a bilateral 3 cm longitudinal pattern. Ex-vivo tensile testing was performed on the BSLEM and compared with three circular myotomies, three spiral myotomies, and three controls.BSLEM was completed in all cases with one esophageal microperforation. The mean operating time was 38 minutes. Over physiologic force ranges of 0 to 100 g, the percentage esophageal elongation was significantly different among the four groups (p<0.05). Spiral myotomy enabled the maximal lengthening among the techniques. BSLEM enabled lengthening significantly greater than controls, but less than both types of surgical myotomy.BSELM is feasible and allows significant esophageal lengthening. Unlike surgical myotomies, BSELM enables selective division of circular fibers to potentially preserve perfusion near the anastomosis and prevent long-term dilatation. Studies are ongoing to characterize the ideal pattern of selective endoscopic myotomy and long-term effects.

Abstract

To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice.The Stanford Biodesign Medical Technology Innovation Process was used as the innovation template. Over a 4-month period, seven IR faculty and four IR fellow physicians recorded observations. These observations were converted into need statements. One particular need relating to gastrostomy tubes was diligently screened and was the subject of a single formal brainstorming session.Investigators collected 82 observations, 34 by faculty and 48 by fellows. The categories that generated the most observations were enteral feeding (n = 9, 11%), biopsy (n = 8, 10%), chest tubes (n = 6, 7%), chemoembolization and radioembolization (n = 6, 7%), and biliary interventions (n = 5, 6%). The output from the screening on the gastrostomy tube need was a specification sheet that served as a guidance document for the subsequent brainstorming session. The brainstorming session produced 10 concepts under three separate categories.This formalized innovation process generated numerous observations and ultimately 10 concepts to potentially to solve a significant clinical need, suggesting that a structured process can help guide an IR practice interested in medical innovation.

Abstract

Accurate assessment of resident competency is a fundamental requisite to assure the training of physicians is adequate. In surgical disciplines, structured tests as well as ongoing evaluation by faculty are used for evaluating resident competency. Although structured tests evaluate content knowledge, faculty ratings are a better measure of how that knowledge is applied to real-world problems. In this study, we sought to explore the performance of surgical residents in a simulation exercise (strategic management simulations [SMS]) as an objective surrogate of real-world performance.Forty surgical residents participated in the SMS simulation that entailed decision making in a real-world-oriented task situation. The task requirements enable the assessment of decision making along several parameters of thinking under both crisis and noncrisis situations. Performance attributes include "simpler" measures of competency (activity level), intermediate categories (information management and emergency responses) to complex measures (breadth of approach and strategy). Scores obtained in the SMS were compared with the scores obtained on the American Board of Surgery In-Training Examination (ABSITE).The data were intercorrelated and subjected to a multiple regression analysis with ABSITE as the dependent variable and simulation scores as independent variables. Using a 1-tail test analysis, only 3 simulation variables correlated with performance on ABSITE at the .01 level (ie, basic activity, focused activity, task orientation). Other simulation variables showed no meaningful relationships to ABSITE scores at all.The more complex real-world-oriented decision-making parameters on SMS did not correlate with ABSITE scores. We believe that techniques such as the SMS, which focus on critical thinking, complement assessment of medical knowledge using ABSITE. The SMS technique provides an accurate measure of real-world performance and provides objective validation of faculty ratings.

NOTES and Other Emerging Trends in Gastrointestinal Endoscopy and Surgery: The Change That We Need and the Change That Is RealAMERICAN JOURNAL OF GASTROENTEROLOGYPasricha, P. J., Krummel, T. M.2009; 104 (10): 2384-2386

Abstract

In this inaugural year of a historic presidency, gastroenterologists and gastrointestinal surgeons may well want to turn their attention to more immediate transformative events that have the potential to revolutionize their own practice in the near future. The most visible and, perhaps, controversial of these is natural orifice transluminal endoscopic surgery (NOTES), but other equally important changes are emerging as investigators around the globe vie with one another in the demonstration of increasingly audacious procedures. As is to be expected, we are also already seeing a backlash from more conservative scholars attempting to temper what they believe to be the surgical equivalent of irrational exuberance. However, by far the most common attitude among gastroenterologists toward these changes is one of indifference. In this piece, we discuss the circumstances that led to the development of NOTES and other innovative procedures, the peril that lies in ignoring them, and the true promise that they hold for our specialties.

Abstract

Simulator-based endovascular skills training measurably improves performance in catheter-based image-guided interventions. The purpose of this study was to determine whether structured global performance assessment during endovascular simulation correlated well with trainee-reported procedural skill and prior experience level.Fourth-year and fifth-year general surgery residents interviewing for vascular fellowship training provided detailed information regarding prior open vascular and endovascular operative experience. The pretest questionnaire responses were used to separate subjects into low (<20 cases) and moderate (20 to 100) endovascular experience groups. Subjects were then asked to perform a renal angioplasty/stent procedure on the Procedicus Vascular Intervention System Trainer (VIST) endovascular simulator (Mentice Corporation, Gothenburg, Sweden). The subjects' performance was supervised and evaluated by a blinded expert interventionalist using a structured global assessment scale based on angiography setup, target vessel catheterization, and the interventional procedure. Objective measures determined by the simulator were also collected for each subject. A postsimulation questionnaire was administered to determine the subjects' self-assessment of their performance.Seventeen surgical residents from 15 training programs completed questionnaires before and after the exercise and performed a renal angioplasty/stent procedure on the endovascular simulator. The beginner group (n = 8) reported prior experience of a median of eight endovascular cases (interquartile range [IQR], 6.5-17.8; range, 4-20), and intermediate group (n = 9) had previously completed a median of 42 cases (IQR, 31-44; range, 25-89, P = .01). The two groups had similar prior open vascular experience (79 cases vs 75, P = .60). The mean score on the structured global assessment scale for the low experience group was 2.68 of 5.0 possible compared with 3.60 for the intermediate group (P = .03). Scores for subcategories of the global assessment score for target vessel catheterization (P = .02) and the interventional procedure (P = .05) contributed more to the differentiation between the two experience groups. Total procedure time, fluoroscopy time, average contrast used, percentage of lesion covered by the stent, placement accuracy, residual stenosis rates, and number of cine loops utilized were similar between the two groups (P > .05).Structured endovascular skills assessment correlates well with prior procedural experience within a high-fidelity simulation environment. In addition to improving endovascular training, simulators may prove useful in determining procedural competency and credentialing standards for endovascular surgeons.

Abstract

: Training surgical residents to manage critically injured patients in a timely fashion presents a significant challenge. Simulation may have a role in this educational process, but only if it can be demonstrated that skills learned in a simulated environment translate into enhanced performance in real-life trauma situations.: A five-part, scenario-based trauma curriculum was developed specifically for this study. Midlevel surgical residents were randomized to receiving this curriculum in didactic lecture (LEC) fashion or with the use of a human performance simulator (HPS). A written learning objectives test was administered at the completion of the training. The first four major trauma resuscitations performed by each participating resident were captured on videotape in the emergency department and graded by two experienced judges blinded to the method of training. The assessment tool used by the judges included an evaluation of both initial trauma evaluation or treatment skills (part I) and crisis management skills (part II) as well as an overall score (poor/fail, adequate, or excellent).: The two groups of residents received almost identical scores on the posttraining written test. Average SIM and LEC scores for part I were also similar between the two groups. However, SIM-trained residents received higher overall scores and higher scores for part II crisis management skills compared with the LEC group, which was most evident in the scores received for the teamwork category (p = 0.04).: A trauma curriculum incorporating simulation shows promise in developing crisis management skills that are essential for evaluation of critically injured patients.

Abstract

Lack of exposure to surgery in the preclinical years of medical school contributes to students' negative opinions of the field and to low application rates to categorical surgical programs.Forty preclinical medical students attended a series of 16 seminars and practice sessions covering the gamut of surgical specialties and basic technical skills. Students were given a Likert format survey before and after taking the course.Students gave high ratings to course content (4.26/5) and lecturers (4.54/5). Students' confidence in their surgical skills doubled (1.45/5 to 3/5, P < .0001), and their perceived readiness for the surgical clerkship increased by 73% (1.63/5 to 2.82/5, P = .007).The preclinical years offer a promising venue for improving medical student interest and performance in surgery.

Abstract

Current surgical care and technology has evolved over the centuries from the interplay between creative surgeons and new technologies. As both fields become more specialized, that interplay is threatened. A 2-year educational fellowship is described which teaches both the process and the discipline of medical/surgical device innovation. Multi-disciplinary teams (surgeons, engineers, business grads) are assembled to educate a generation of translators, who can bridge the gap between scientific and technologic advances and the needs of the physician and the patient.

Abstract

To describe the field of surgical innovation from a historical perspective, applying new findings from research in technology innovation.While surgical innovation has a rich tradition, as a field of study it is embryonic. Only a handful of academic centers of surgical innovation exist, all of which have arisen within the last 5 years. To this point, the field has not been well defined, nor have future options to promote surgical innovation been thoroughly explored. It is clear that surgical innovation is fundamental to surgical progress and has significant health policy implications. A process of systematically evaluating and promoting innovation in surgery may be critical in the evolving practice of medicine.A review of the academic literature in technology innovation was undertaken. Articles and books were identified through technical, medical, and business sources. Luminaries in surgical innovation were interviewed to develop further relevance to surgical history. The concepts in technology innovation were then applied to innovation in surgery, using the historical example of surgical endoscopy as a representative area, which encompasses millennia of learning and spans multiple specialties of care.The history of surgery is comprised largely of individual, widely respected surgeon innovators. While respecting individual accomplishments, surgeons as a group have at times hindered critical innovation to the detriment of our profession and patients. As a clinical discipline, surgery relies on a tradition of research and attracting the brightest young minds. Innovation in surgery to date has been impressive, but inconsistently supported.A body of knowledge on technology innovation has been developed over the last decade but has largely not been applied to surgery. New surgical innovation centers are working to define the field and identify critical aspects of surgical innovation promotion. It is our responsibility as a profession to work to understand innovation in surgery, discover, translate, and commercialize advances to address major clinical problems, and to support the future of our profession consistently and rationally.

Abstract

Progress in surgical science has been characterized by a continuous cycle of innovation from bedside to bench to bedside. Beginning 30,000 years ago with the first bone needles to surgical lasers and robotics of today, each quantum leap has resulted from the convergence of technical advances and creative surgeons, but always defined by an attitude of care toward the sick. One of the most innovative pediatric surgeons, Dr. Mark Ravitch, elucidated some simple yet profound principles in the precise answer to the question "What is Surgery?" This section outlines some simple concepts summarized as "Ravitch's Rules," which provide a useful framework for clarity in understanding the past and illuminating the road ahead. Surgeons must be thoughtful in how they define themselves and their craft, ignoring technological advances at their own peril.

Abstract

Ethical issues in pediatric research have long been debated, and experimentation in pediatric surgery is under intense scrutiny. Extensive legislation and institutional systems that attempt to protect children while supporting necessary research are at times ineffective. Pediatric surgery has less funding and resources for innovation than fields with higher clinical volume. Not unlike pediatrics in general, innovation in pediatric surgery must be beyond criticism. And yet, for the sake of patients, innovation should not only be maintained, but must be encouraged.

Abstract

The scarless fetal skin-healing mechanism is mediated in part by the fibroblast and involves differential expression of transforming growth factor (TGF)-beta isoforms 1 and 3. The authors hypothesized that fetal and adult fibroblasts respond differently to TGF-beta isoform-specific stimulation, which may influence whether wounds scar. Connective tissue growth factor (CTGF), Smad3, and Smad7 are TGF-beta target genes. Expression of these targets was quantitated after TGF-beta1 and -beta3 stimulation of fetal and adult fibroblasts.Primary mouse fibroblast cultures at gestational day 16.5 (E17), 18.5 (E19), and 6 weeks (adult) were stimulated with TGF-beta1 or TGF-beta3. Quantitative polymerase chain reaction was performed for CTGF, Smad3, and Smad7 expression.CTGF was reduced four-fold in E17 and E19 compared with adult fibroblasts (p < 0.005). After TGF-beta1 stimulation, CTGF expression increased more than 60-fold in both E17 and E19 (p < 0.01), which was three-fold greater than that in adult fibroblasts (p < 0.005). TGF-beta3 induced more than 70-fold, 50-fold, and 20-fold increases in CTGF expression in E17, E19, and adult fibroblasts, respectively (p < 0.01 for each). Both TGF-beta1 and -beta3 decreased Smad3 expression and increased Smad7 expression in each fibroblast type, suggesting that intact TGF-beta-mediated signaling pathways were present.Fetal (E17 and E19) fibroblasts have lower CTGF expression compared with adult fibroblasts. However, fetal fibroblasts have larger increases in CTGF expression after TGF-beta1 or -beta3 stimulation. Fetal and adult mouse fibroblasts have similar TGF-beta1 and TGF-beta3 transcriptional regulation of Smad3 and Smad7. This suggests that scarless healing is likely not mediated by different Smad-dependent transcriptional responses to TGF-beta isoforms in the fetal E17 fibroblast.

Abstract

The purpose of this study was to develop a reproducible murine model of fetal scarless wound healing.One-millimeter excisional wounds were made in fetal skin at gestational days 16.5 (E17) and 18.5 (E19) (term = day 21.5, or E22) and marked with India ink. Fetal mortality was less than 30 percent in E17 fetuses and 0 percent in E19 fetuses. Control postnatal 2-mm open wounds were made in 3-week-old mice.At 48 hours, E17 skin wounds had healed completely. E19 skin wounds also healed but were marked by skin irregularity at the wound site. Histologically, E17 wounds had fine reticular collagen architecture by trichrome staining and hair follicle regeneration. In contrast, E19 wounds healed with collagen deposition and scar formation and no hair follicle regeneration.The authors have developed a reliable mouse model of fetal scarless repair to help elucidate the mechanism of scarless wound healing to take advantage of genetically modified animals. The knowledge gained may be used to manipulate scarring in the adult to produce a more fetal-like wound.

Abstract

Choledochal cyst resection and hepaticojejunostomy have historically been performed using an open technique. We describe here the largest single experience with this procedure using laparoscopic techniques in eight consecutive pediatric patients.There were six girls and two boys, of ages ranging from 3 months to 13 years. All had type I choledochal cysts. Three were asymptomatic, having been noted on prenatal ultrasonography. Five ports were utilized: one 5-mm telescope port at the umbilicus, two 3-mm operating ports on both sides of the umbilicus, one 5-mm left subcostal port for liver retraction, and one LLQ 5-mm assistant port.The median operating time was 155 min (range 110-250 min), with one conversion to an open procedure due to a high transection of the cyst leading to partial retraction of the left hepatic duct into the liver substance. Mean hospital stay was 3 days. At a mean follow-up of 18.8 months, all patients were anicteric and asymptomatic.Laparoscopic resection of choledochal cysts can be performed safely in pediatric patients with minimal morbidity and good long-term results.

Abstract

Adult MRL/MpJ mice regenerate cartilage during repair of through-and-through ear punch wounds. However, the ability of this mouse strain to heal isolated cutaneous wounds by regeneration or with scar is unknown. The purpose of this study was to characterize the rate of reepithelialization and collagen architecture in dermal wounds from MRL/MpJ mice compared with C57bl/6 and Balb/c strains. Full-thickness incisional (5 mm) and excisional (2 mm diameter) skin wounds were made on the dorsum of 7-week-old MRL/MpJ, C57bl/6, and Balb/c mice. Ear punch wounds were made simultaneously on each animal. Reepithelialization was complete by 48 hours for incisional skin wounds in each strain. All excisional wounds showed incomplete reepithelialization at 24, 48, and 72 hours. At 14 days, all skin wounds had grossly healed. In contrast to the ear wounds made in C57bl/6 and Balb/c mice, MRL/MpJ ear wounds were completely healed by day 28. Dorsal skin wound sections at 14 and 28 days revealed dense collagen deposition and similar degrees of fibrosis between the three strains of mice. In conclusion, in contrast to wound healing in the ear, MRL/MpJ mouse dorsal cutaneous wounds heal similarly to C57bl/6 and Balb/c mice with dermal collagen deposition and scar formation.

Abstract

Simulation offers a new frontier in surgical education that promises to enhance the current approaches to training. It addresses the operational and fiscal realities of current healthcare deliveries while adhering to principles of educational psychology. Challenges for educators include systematic validation of simulation methods, attracting research funding agencies to support this cause, and development of appropriate funding mechanisms for the sometimes high facility and hardware costs. The greatest challenge, however, is instituting simulation into the minds of a surgical community that is already steeped in a long and entrenched tradition of Halstedian surgical training.

Abstract

Portal vein thrombosis (PVT) following open splenectomy is a potentially lethal complication with an incidence of up to 6%. The objective of this report is to describe our management of a recent laparoscopic case, discuss current therapies, and consider antiplatelet therapy for prophylaxis.Medical records, laboratory studies, and imaging studies pertaining to a recent case of a laparoscopic splenectomy were examined. Current literature related to this topic was reviewed.A 16-year-old girl underwent laparoscopic splenectomy for idiopathic thrombocytopenic purpura. Her preoperative platelet count was 96K. She was discharged on postoperative day 1 after an uneventful operation including division of the splenic hilum with an endoscopic linear stapler. On postoperative day 20, she presented with a 5-day history of epigastric pain, nausea, and low-grade fevers without peritoneal signs. Her white blood cell count was 17.3; her platelets were 476K. Computed tomography demonstrated thrombosis of the splenic, superior mesenteric, and portal veins propagating into the liver. Heparinization was begun followed by an unsuccessful attempt at pharmacologic and mechanical thrombolysis by interventional radiology. Over the next 5 days, her pain resolved, she tolerated a full diet, was converted to oral anticoagulation and sent home. Follow-up radiographic studies demonstrated the development of venous collaterals and cavernous transformation of the portal vein.No standard therapy for PVT exists; several approaches have been described. These include systemic anticoagulation, systemic or regional medical thrombolysis, mechanical thrombolysis, and surgical thrombectomy. Unanswered questions exist about the most effective acute therapy, duration of anticoagulation, and the potential efficacy of routine prophylaxis with perioperative antiplatelet agents. PVT following splenectomy occurs with both the open and laparoscopic approach.

Abstract

Over the last two decades, virtual reality, haptics, simulators, robotics, and other "advanced technologies" have emerged as important innovations in medical learning and practice. Reports on simulator applications in medicine now appear regularly in the medical, computer science, engineering, and popular literature. The goal of this article is to review the emerging intersection between advanced technologies and surgery and how new technology is being utilized in several surgical fields, particularly plastic surgery. The authors also discuss how plastic and reconstructive surgeons can benefit by working to further the development of multimedia and simulated environment technologies in surgical practice and training.

Abstract

It has been nearly 20 years since the first appearance of robotics in the operating room. In that time, much progress has been made in integrating robotic technologies with surgical instrumentation, as evidenced by the many thousands of successful robot-assisted cases. However, to build on past success and to fully leverage the potential of surgical robotics in the future, it is essential to maximize a shared understanding and communication among surgeons, engineers, entrepreneurs, and healthcare administrators. This article provides an introduction to medical robotic technologies, develops a possible taxonomy, reviews the evolution of a surgical robot, and discusses future prospects for innovation. Robotic surgery has demonstrated some clear benefits. It remains to be seen where these benefits will outweigh the associated costs over the long term. In the future, surgical robots should be smaller, less expensive, easier to operate, and should seamlessly integrate emerging technologies from a number of different fields. Such advances will enable continued progress in surgical instrumentation and, ultimately, surgical care.

Abstract

Computer-enhanced robotic surgical systems have been increasingly used to facilitate complex minimal access surgical procedures. In adult patients, such systems have been used to perform a wide variety of operations including coronary artery bypass grafting, mitral valve repair, Roux-en-Y gastric bypass, colon resection, nephrectomy, and radical prostatectomy. In the field of pediatric surgery, the experience with robotic surgical systems has been more limited. However, with improvements in robotic technology, interest and experience with robotic pediatric surgery have grown rapidly. The purpose of this article is to review the current experimental and clinical literature regarding the use of robotic surgical systems in the pediatric patient population.

Abstract

To determine participant perceptions of Emergency Medicine Crisis Resource Management (EMCRM), a simulation-based crisis management course for emergency medicine.EMCRM was created using Anesthesia Crisis Resource Management (ACRM) as a template. Thirteen residents participated in one of three pilot courses of EMCRM; following a didactic session on principles of human error and crisis management, the residents participated in simulated emergency department crisis scenarios and instructor-facilitated debriefing. The crisis simulations involved a computer-enhanced mannequin simulator and standardized patients. After finishing the course, study subjects completed a horizontal numerical scale survey (1 = worst rating to 5 = best rating) of their perceptions of EMCRM. Descriptive statistics were calculated to evaluate the data.The study subjects found EMCRM to be enjoyable (4.9 +/- 0.3) (mean +/- SD) and reported that the knowledge gained from the course would be helpful in their practices (4.5 +/- 0.6). The subjects believed that the simulation environment prompted realistic responses (4.6 +/- 0.8) and that the scenarios were highly believable (4.8 +/- 0.4). The participants reported that EMCRM was best suited for residents (4.9 +/- 0.3) but could also benefit students and attending physicians. The subjects believed that the course should be repeated every 8.2 +/- 3.3 months.The EMCRM participants rated the course very favorably and believed that the knowledge gained would be beneficial in their practices. The extremely positive response to EMCRM found in this pilot study suggests that this training modality may be valuable in training emergency medicine residents.

Abstract

To establish the construct validity of a virtual reality-based upper gastrointestinal endoscopy simulator as a tool for the skills training of residents.Previous studies have demonstrated the relevance of virtual reality training as an adjunct to traditional operating room learning for residents. The use of specific task trainers, which have the ability to objectively analyze and track user performance, has been shown to demonstrate improvements in performance over time. Using this off-line technology can lessen the financial and ethical concerns of using operative time to teach basic skills.Thirty-five residents and fellows from General Surgery and Gastrointestinal Medicine were recruited for this study. Their performance on virtual reality upper endoscopy tasks was analyzed by computer. Assessments were made on parameters such as time needed to finish the examination, completeness of the examination, and number of wall collisions. Subjective experiences were queried through questionnaires. Users were grouped according to their prior level of experience performing endoscopy.Construct validation of this simulator was demonstrated. Performance on visualization and biopsy tasks varied directly with the subjects' prior experience level. Subjective responses indicated that novice and intermediate users felt the simulation to be a useful experience, and that they would use the equipment in their off time if it were available.Virtual reality simulation may be a useful adjunct to traditional operating room experiences. Construct validity testing demonstrates the efficacy of this device. Similar objective methods of skills evaluation may be useful as part of a residency skills curriculum and as a means of procedural skills testing.

Abstract

To evaluate construct and content validity as well as learners' perceptions of CathSim, a virtual reality intravenous (IV) insertion simulator.A prospective cohort study design was employed to determine construct validity, and a participant survey was used to ascertain content validity as well as user perceptions of CathSim. Forty-one attendings, residents, and medical students in emergency medicine and anesthesia attempted five simulated IV insertions on CathSim. Subject performances were scored by the computer, and subject perceptions of the simulator were measured using a Likert scale questionnaire (1 = worst rating; 5 = best rating). The subjects were divided into three groups (novices, intermediates, and experts) based on previous IV experience. To determine construct validity, performances of the three groups were compared using one-way analysis of variance (ANOVA). To determine content validity, the experts' perceptions of the simulator's realism and usefulness were assessed. Study subjects' perceptions of the simulator's ease of use and overall appeal were analyzed.The experts scored better than the others in five of nine scoring parameters (p < 0.05). The experts rated the realism of CathSim's four major simulation components at 3.85, 3.46, 3.69, and 3.46; the overall realism of CathSim at 2.93; and its utility for medical student training at 4.57. The simulator's ease of use was rated at 2.34 by all subjects. Novices reported a score of 4.59 regarding their likelihood to use the simulator.CathSim demonstrated construct validity in five of nine internal scoring parameters and was judged to be adequately realistic and highly useful for medical student training. Despite being difficult to learn to use, it remained appealing to the users, especially the novices.

Abstract

Early gestation mammalian fetuses possess the remarkable ability to heal cutaneous wounds in a scarless fashion. Over the past 20 years, scientists have been working to decipher the mechanisms underlying this phenomenon. Much of the research to date has focused on fetal correlates of adult wound healing that promote fibrosis and granulation tissue formation. It is important to remember, however, that wound repair consists of a balance between tissue synthesis, deposition, and degradation. Relatively little attention has been paid to this latter component of the fetal wound healing process. In this study, we examined the ontogeny of ten matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in nonwounded fetal rat skin and fibroblasts as a function of gestational age. We used a semiquantitative polymerase chain reaction protocol to analyze these important enzymes at time points that represent both the scarless and scar-forming periods of rat gestation. The enzymes evaluated were collagenase-1 (MMP-1), stromelysin-1 (MMP-3), gelatinase A (MMP-2), gelatinase B (MMP-9), membrane-type matrix metalloproteinases (MT-MMPs) 1, 2, and 3, and TIMPs 1, 2, and 3. Results demonstrated marked increases in gene expression for MMP-1, MMP-3 and MMP-9 that correlated with the onset of scar formation in nonwounded fetal skin. Similar results were noted in terms of MMP-9 gene expression in fetal fibroblasts. These results suggest that differences in the expression of these matrix metalloproteinases may have a role in the scarless wound healing phenotype observed early in fetal rat gestation. Furthermore, our data suggest that the differential expression of gelatinase B (MMP-9) may be mediated by the fetal fibroblasts themselves.

Abstract

The traditional system of clinical education in emergency medicine relies on practicing diagnostic, therapeutic, and procedural skills on live patients. The ethical, financial, and practical weaknesses of this system are well recognized, but the alternatives that have been explored to date have shown even greater flaws. However, ongoing progress in the area of virtual reality and computer-enhanced simulation is now providing educational applications that show tremendous promise in overcoming most of the deficiencies associated with live-patient training. It will be important for academic emergency physicians to become more involved with this technology to ensure that our educational system benefits optimally.

Abstract

Disposable trocars with safety shields are widely used for laparoscopic access. The aim of this study was to analyze risk factors associated with injuries resulting from their use as reported to the Food and Drug Administration.Manufacturers are required to report medical device-related incidents to the Food and Drug Administration. We analyzed the 629 trocar injuries reported from 1993 through 1996.There were three types of injury: 408 injuries of major blood vessels, 182 other visceral injuries (mainly bowel injuries), and 30 abdominal wall hematomas. Of the 32 deaths, 26 (81%) resulted from vascular injuries and 6 (19%) resulted from bowel injuries. Eighty-seven percent of deaths from vascular injuries involved the use of disposable trocars with safety shields and 9% involved disposable trocars with a direct-viewing feature. The aorta (23%) and inferior vena cava (15%) were the vessels most commonly traumatized in the fatal vascular injuries. Ninety-one percent of bowel injuries involved trocars with safety shields and 7% involved direct-view trocars. The diagnosis of an enterotomy was delayed in 10% of cases, and the mortality rate in this group was 21%. In 41 cases (10%) the surgeon initially thought the trocar had malfunctioned, but in only 1 instance was malfunction subsequently found when the device was examined. The likelihood of injury was not related to any specific procedure or manufacturer.These data show that safety shields and direct-view trocars cannot prevent serious injuries. Retroperitoneal vascular injuries should be largely avoidable by following safe techniques. Bowel injuries often went unrecognized, in which case they were highly lethal. Device malfunction was rarely a cause of trocar injuries.

Abstract

In the United States, medical care consumes approximately $1.2 trillion annually (14% of the gross domestic product) and involves 250,000 physicians, almost 1 million nurses, and countless other providers. While the Information Age has changed virtually every other facet of our life, the education of these healthcare professionals, both present and future, is largely mired in the 100-year-old apprenticeship model best exemplified by the phase "see one, do one, teach one." Continuing medical education is even less advanced. While the half-life of medical information is less than 5 years, the average physician practices 30 years and the average nurse 40 years. Moreover, as medical care has become increasingly complex, medical error has become a substantial problem. The current convulsive climate in academic health centers provides an opportunity to rethink the way medical education is delivered across a continuum of professional lifetimes. If this is well executed, it will truly make medical education better, safer, and cheaper, and provide real benefits to patient care, with instantaneous access to learning modules. At the Center for Advanced Technology in Surgery at Stanford we envision this future: within the next 10 years we will select, train, credential, remediate, and recredential physicians and surgeons using simulation, virtual reality, and Web-based electronic learning. Future physicians will be able to rehearse an operation on a projectable palpable hologram derived from patient-specific data, and deliver the data set of that operation with robotic assistance the next day.

Abstract

The teaching and learning of surgery is a time-honored tradition based upon the "see one, do one, teach one" apprenticeship model. Recent improvement of this model has centered upon incremental change in skills teaching and testing and curricular development. Economic pressures have strained the resources of academic health centers and faculty responsible for teaching surgery, even as information technology has opened new avenues for obtaining and benefitting from relevant information. Combining the tools of simulation theory, virtual reality, and the principles of adult education offers new opportunities to optimize surgical education as we enter a more highly connected and interdependent era, where the boundaries between teacher and student blur as the modern surgeon truly becomes a lifelong learner.

Abstract

Lumbar punctures (LP) are complex, precise procedures done to obtain cerebro-spinal fluid from a patient for diagnostic purposes. Incorrect techniques resulting from inadequate training or supervision can result in sub-optimal outcomes. As tactile feedback is crucial for a successful lumbar puncture, this procedure serves as an ideal candidate for the development of a haptic training simulator. The intent of this project is to engineer a force feedback LP simulator that provides a safe method of training students (medical students, residents, or trained physicians) for an actual LP procedure on a patient.

Abstract

Rapid change is under way on several fronts in medicine and surgery. Advances in computing power have enabled continued growth in virtual reality, visualization, and simulation technologies. The ideal learning opportunities afforded by simulated and virtual environments have prompted their exploration as learning modalities for surgical education and training. Ongoing improvements in this technology suggest an important future role for virtual reality and simulation in surgical education and training.

Abstract

The results of extracorporeal membrane oxygenation (ECMO) following repair of congenital diaphragmatic hernia (CDH) are analyzed for 93 neonates reported to the Neonatal ECMO Registry. Each infant was symptomatic at birth and developed life-threatening hypoxemia after herniorrhaphy. ECMO was used after neonates met criteria predictive of death in individual centers. These included (1) failure of medical therapy to reverse hypoxemia (35 neonates); (2) acute clinical deterioration making death appear likely (37 neonates); (3) AaDO2 greater than 600 for 8 hours (13 neonates); (4) oxygen index score of 51 for 4.8 hours (5 neonates); and (5) cardiac arrest (1 neonate). With ECMO, 52 infants (58%) survived and were discharged. Pre-ECMO arterial blood gas analysis was not predictive of outcome. Mortality was higher in small premature infants. ECMO corrected the hypoxemia, which usually causes death following congenital diaphragmatic herniorrhaphy. Unfortunately, 47 major bleeding complications occurred with 29 deaths. Therefore, improved survival may depend on new methods designed to prevent bleeding.

Abstract

From 1981 through 1986, 8 newborns with congenital diaphragmatic hernia required herniorrhaphy in the first 8 hours of life. Extracorporeal membrane oxygenation (ECMO) was employed in 7 after they met local criteria predictive of 95% mortality. These criteria were an alveolar-postductal arterial oxygen gradient greater than 600 mm Hg for 12 hours or hemodynamic instability. Four of these 7 patients had unremitting hypoxemia after herniorrhaphy (no "honeymoon" period), 3 of whom survived. One additional patient died, producing a mortality of 29%. ECMO used for 68 to 241 hours (mean, 163 hours) provided reliable oxygenation in all. Deaths resulted from disseminated intravascular coagulation and bleeding, and bleeding and pulmonary failure after ligation of a patent ductus arteriosus. Complications occurred in 6 patients and included bleeding (3), hernia recurrence (3), and air embolism (1). Follow-up ranging from 1 year to 6 years after discharge of the 5 survivors shows normal growth and development in 4. The reported mortality without ECMO following congenital diaphragmatic herniorrhaphy in the first 8 hours of life ranges between 60 and 80%. While bleeding may present problems, survival of newborns with refractory hypoxemia after diaphragmatic repair has improved with ECMO.

Abstract

Fetal, neonatal, and adult tissue response to a standardized injury was studied using subcutaneous wound implants, linear incisions, and punch wounds in New Zealand white rabbits. In the fetus, sutured incisions healed by primary intention without antecedent inflammation. However, neither contraction nor healing by secondary intention was seen in punch or unsutured wounds. Healing both by primary and secondary intention following inflammatory infiltration was observed uniformly in neonatal and adult rabbits. Wound implants were extensively infiltrated with collagen in the adults studied; however, no collagen was seen in fetal implants and collagen hydroxyproline content could not even be detected by high performance liquid chromatography techniques; rather, a matrix rich in hyaluronic acid was found. The fetal tissue response to injury differs from the adult, proceeding in the absence of a classical inflammatory stimulus and lacking contractile capabilities. The deposition of extracellular matrix rich in hyaluronic acid but devoid of collagen suggests that the fetal response to injury may be a process more closely resembling regeneration or growth rather than repair by scar deposition.

Abstract

Continence can be preserved by several operations following proctocolectomy for ulcerative colitis. The Swenson procedure, used for congenital megacolon, may be applied for reconstruction following proctocolectomy for other colonic disease. Rectal eversion and resection to the dentate line obviates the need for mucosectomy and permits ileoanal anastomosis with excellent exposure. Two girls, 9 and 11 years of age, underwent proctocolectomy, formation of an ileal J-pouch, and a Swenson pull-through with ileoanal anastomosis. One year following closure of diverting ileostomies, both children have 2 to 3 continent bowel movements daily with very rare nocturnal soiling. Anal manometry is normal. The application of this method for ileoanal anastomosis may broaden the choice of operations for selected children requiring proctocolectomy.

Abstract

Current selection criteria necessary for intelligent application of extracorporeal membrane oxygenation (ECMO) in hypoxic neonates remains controversial. Both the Neonatal Pulmonary Insufficiency Index (NPII) and serial alveolar-arterial oxygenation gradient measurements (A-a)Do2 have been recommended. Accordingly, an analysis of 50 consecutive severely hypoxic neonates was undertaken to assess the predictive value of (A-a)Do2 determinations and NPII in discriminating survivors from non-survivors. These infants with meconium aspiration syndrome (MAS), congenital diaphragmatic hernia (CDH), or persistent pulmonary hypertension of the newborn (PPHN) required maximum mechanical ventilation for hypoxia. Pharmacologic manipulation of pulmonary vascular resistance was attempted in 83%. If postductal (A-a)Do2 remained greater than or equal to 620 torr despite 12 hours of maximum medical therapy, mortality was 100%; however, 35% of nonsurvivors were unfortunately excluded. (A-a)Do2 greater than or equal to 600 torr for 12 hours demonstrated 93.8% mortality, and only 12% of all mortalities were thus excluded. Among nonsurvivors successfully hyperventilated, the NPII could not predict mortality. Ideal selection criteria must exclude those who would otherwise survive without ECMO, yet allow early accurate identification of the neonate certain to die. It would appear that serial (A-a)Do2 determinations best permit this identification and thus orderly application of ECMO.

Abstract

A case of colitis cystica profunda in a 14-year-old male is presented. The clinical and pathologic management are reviewed. Differentiation from adenocarcinoma by careful histologic evaluation of the epithelium is fundamental in avoiding overtreatment.

Abstract

Eight infants with intractable respiratory failure were treated with extracorporeal membrane oxygenation. Intractable respiratory failure was defined as alveolar-arterial oxygen gradient of more than 620 torr for six to 12 hours that did not respond to hyperventilation and the use of tolazoline. Infants with overt sepsis, CNS damage, or other debilitating conditions were not considered for extracorporeal membrane oxygenation. Six of the eight infants survived after a mean extracorporeal membrane oxygenation time of 164 hours. Five of the six survivors were normal neurologically and developmentally when examined at 1 year of age.

Abstract

Pulmonary failure is the most frequent cause of mortality in newborns, accounting for 15,000 deaths yearly. It may be the result of the respiratory distress syndrome (RDS), meconium aspiration syndrome (MAS), or persistent fetal circulation (PFC), including infants with congenital diaphragmatic hernia (CDH). Early identification of patients with predictably fatal but potentially reversible respiratory failure refractory to conventional management protocols would permit orderly application of extracorporeal membrane oxygenation (ECMO) as a final resuscitative measure. Eight neonates with severe pulmonary failure manifested by A-a DO2 of greater than 620 torr for greater than 12 hr, persistent cardiovascular instability, and relentless progression of acidosis and hypoxemia were predicted to have a 100% mortality in spite of maximal medical therapy. Four patients presented with MAS and 4 others had PFC, including 2 with CDH. All were supported with ECMO using the internal jugular vein and common carotid artery for access to the right atrium and aortic arch. Following support for 77-313 hr, 6 were successfully weaned from ECMO and then from the ventilator. In these few patients the use of extracorporeal membrane oxygenation after exhaustion of standard therapy was accomplished safely and successfully without untoward short-term sequelae. Extracorporeal ventilatory support may purchase the critical time necessary for resolution of the underlying parenchymal disease, including the pulmonary hypertension associated with CDH.